One of the things that has confused many about the coronavirus is the following: What in some people turns out to be an illness characterized by minor flu-like symptoms, in others can cause serious illness and death. Why are there such differences? American researchers have taken a closer look at that. And they believe they have found new answers. They have discovered that a fairly common gene variant can lead to increased mortality if you become infected with covid-19. And this variant has over 230 million people in the world. – Both age, gender and certain diseases increase the risk of harmful outcomes. But that doesn’t explain everything. This is the first time we have seen that such a common gene variant is associated with covid and mortality, says Professor Sohail Tavazoie. He is employed by The Rockefeller University and has led the study. The study has been published in the renowned journal Nature. Much to say to many The researchers have carried out their new study using mice. They have previously shown that mice with gene variants linked to Alzheimer’s have a greater risk of dying if they are infected with the coronavirus. Now a new analysis suggests that people with the same variants can also suffer the same fate. The discovery could mean a lot to millions of people. Four important letters Tavazoie and his colleagues have previously studied a gene called APOE. This plays a role in cancer and metastases. After finding out what this gene can do, the researchers began to look more closely at its various forms. Most people have a form of the gene called APOE3. While 40 percent of the population has at least one copy of the APOE2 or APOE4 variant. APOE4 is primarily known to increase the risk of Alzheimer’s. The researchers became curious as to whether these gene variants could also be linked to corona. – We had only looked at diseases that are not contagious. But what if APOE variants also make people vulnerable to SARS-CoV-2? And quite rightly… The coronavirus has killed just under 7 million people worldwide. Photo: Waltraud Grubitzsch / AP Striking result The results of the experiments showed that mice with the gene variants APOE2 and APOE4 were more likely to die if they were infected with the virus. The difference between these gene variants is about the amount of amino acids. And it shouldn’t be about very many. – The results are striking. One to two amino acids were sufficient to cause large differences in survival among mice, says Benjamin Ostendorf. He is the lead author of the study. Mice with APOE2 and APOE4 also had more virus replicating in the lungs, as well as more signs of inflammation and tissue damage. But what about us? New studies required When the animal study was finished, the researchers began to look at humans. Here they used the British biobank. It contains health data from half a million Britons. In an analysis of 13,000 patients, the researchers found that people with two copies of either APOE4 or APOE2 were more likely to have died as a result of covid-19. About 3 percent of individuals have two copies of these variants. It represents an estimated 230 million people in the world. Sohail Tavazoie nevertheless emphasizes that this is not proof that everyone who carries just one of these alleles has an increased risk. He points out, among other things, that vaccination has changed this. – Several of these individuals who died early could have been protected by a vaccine. Going forward, the researchers hope to be able to look at prospective studies. Then one can perhaps find the connection between APOE and distinct covid outcomes. If future studies confirm the same, for example people with these gene variants can get the help they need faster, as well as be prioritized when it comes to vaccines. Findings that support each other Arne Søraas is a researcher and infectious disease doctor. He himself researches the coronavirus with a special focus on long covid. He thinks the new study is exciting. – I think that the study gives us a kind of explanation as to why some people get sicker than others from covid. He says these are findings that also support theories in his research. Among other things, they have seen that getting sicker from corona also more often causes long covid afterwards. Søraas also says that in Finnish studies it has been seen that microbleeds in the brain and more severe fatigue are more often found among patients with the APOE4 variant. – So here there are many findings that support each other, says the Norwegian doctor to news. He still does not believe that these findings should scare people. It is a small part of the Norwegian population who will be carriers of the relevant gene copies that increase mortality. Arne Søraas has also led the trance study, which was recently concluded. Here they have looked at whether fish oil can actually prevent us from getting sick from the coronavirus. Photo: Torstein Bøe / news
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Researchers link common gene variant to coronavirus and mortality – news Trøndelag
